ICEBERG_COLUMNS
Provides column information for Iceberg external tables.
	Provides column information for Iceberg external tables. The information in this table is drawn from the Iceberg metadata files at query time.
| Column Name | Data Type | Description | 
|---|---|---|
| TABLE_ID | INTEGER | Catalog-assigned numeric value that uniquely identifies the table. | 
| TABLE_SCHEMA | VARCHAR | Name of the table's schema. If the schema belongs to a non-default namespace in an Eon Mode database, the schema name is front-qualified with the name of the schema's namespace. For example,  | 
| TABLE_NAME | VARCHAR | Name of the table containing the column. | 
| COLUMN_ID | VARCHAR | Catalog-assigned VARCHAR value that uniquely identifies a table column. | 
| COLUMN_NAME | VARCHAR | Name of the column. | 
| DATA_TYPE | VARCHAR | Column data type. | 
| DATA_TYPE_ID | INTEGER | Catalog-assigned unique numeric ID of the data type. | 
| DATA_TYPE_LENGTH | INTEGER | Maximum allowable length of the data type. | 
| CHARACTER_MAXIMUM_LENGTH | VARCHAR | Maximum allowable length of a VARCHAR column. | 
| NUMERIC_PRECISION | INTEGER | Number of significant decimal digits for a NUMERIC column. | 
| NUMERIC_SCALE | INTEGER | Number of fractional digits for a NUMERIC column. | 
| DATETIME_PRECISION | INTEGER | Declared precision for a TIMESTAMP column, or NULL if no precision was declared. | 
| INTERVAL_PRECISION | INTEGER | Number of fractional digits retained in the seconds field of an INTERVAL column. | 
| IS_NULLABLE | BOOLEAN | Whether the column can contain NULL values. | 
| WRITE_DEFAULT | VARCHAR | Field value for any records written after the field was added to the schema, if the writer does not supply the field’s value. | 
| INITIAL_DEFAULT | VARCHAR | Field value for all records that were written before the field was added to the schema. |